In the past, animal identification (e.g., ear tags, ear tattoos, leg bands, etc.) has been used to prove ownership and deter theft of animals, such as livestock. In recent years, concerns about diseases and contamination have increased, thus leading to a domestic push to increase the scope of livestock surveillance. Passive radio frequency identification animal tags have been employed to provide a simple way for a computer to read the identity of an animal and to provide information about that animal from a database. There remains a need for additional methods to monitor the health, well being, activity, or care of animals.